The objective of this project is to characterize:dose-response relationships and toxicity of oxazepam administered in dosed feed to rats and mice in 90-day subchronic and 2-year chronic studies. Animals will be administered dosed feed 7 days per week for 90 days or 2 years. At the end of each study, all animals will be given gross and microscopic histopathologic evaluations, Sperm morphology/vaginal cytology, neurobehavioral evaluations, and blood oxazepam concentrations will be evaluated in the 90-day study. A 65-week interim sacrifice including histopathology and blood oxazepam concentrations will be evaluated in the chronic study. In addition, special neurobehavior indices will be evaluated prior to the start of the chronic study and at 6, 12, 18, and 24 months of the chronic study. The results of the 90-day study will be used by NTP to establish doses to be used in the chronic study. The results of the chronic study will be utilized in evaluation of the toxicologic and carcinogenic potential of oxazepam.